西安机场高速公路桥梁减震系统设计

Design of Seismic Mitigation and Isolation System for a Bridge on Xi′an Airport Expressway

按照新颁布的《公路桥梁抗震设计细则》相关规定,对西安机场高速公路桥梁进行减隔震系统的设计与分析。采用板式橡胶支座和铅销橡胶支座2种方案替代传统的盆式支座,来延长结构的固有周期并分散桥墩的水平地震力。弹性反应谱分析表明2种替代方案都能使结构在中震激励下保持弹性;在大震激励下板式橡胶支座方案中支座的变位、桥墩的塑性变形都接近极限要求,而铅销橡胶支座方案中支座处于正常的工作范围,桥墩基本保持弹性。

The seismic mitigation and isolation system for a bridge on Xi＇an Airport Expressway is designed and analyzed in compliance with the relevant provisions in the latest Guidelines for Seismic Design of Highway Bridges. Two kinds of the alternatives of plate rubber bearing and lead core rubber bearing are used to substitute for the alternative of conventional pot bearing in order to prolong the natural period of the structure of the bridge and disperse the horizontal earthquake force in bridge pier. The results of elastic response spectrum analysis show that the two kinds of the alternatives can all keep the structure elastic under the medium seismic excitation, however under the great seismic excitation, the displacement of the bearing and the plastic deformation of the pier in the alternative of the plate rubber bearing are close to the set limit while in the alternative of the lead core rubber bearing, the bearing still works in normal range and the pier basically remains elastic.